[labawi]

You probably (or at least most people) don't need higher throughput modes in wireless radios. You need good connectivity, which can usually be achieved with a larger number of simpler APs, instead of 8x8 MU-MIMO 3-band 2666Mbit, that only works with manufacturer's firmware.

You can get 3x3MIMO 802.11ac routers with good openwrt compatibility for 60-80$, that should give you gigabit speeds and there are cheaper versions (get at least 2x2 @5GHz). Check for openwrt support before buying. You do not need a rack full of equipment, though you would need to reasonably distribute APs with cables.

APs that are properly distributed, running on minimum TX power, yet close so they use highest rates, will beat every single overpriced AP. May need some adjustment for corner cases.

802.11ac wave2 and especially ax have very useful features, but they are no match for fundamental properties of radio wave propagation.

¹ Close mostly means distance at line-of-reflection for 5GHz channels and line-of-penetration for 2.4GHz.

[glogla]

It also depends where you're living - ferroconcrete apartment building is something else than drywall house.

Also 3x3 only gives you close to gigabit speed (realistically 700 mbps) when both ends are 3x3, and only very expensive and special workstation class laptops (including 15" MacBook Pros which belong in that category at least by pricing) are that.

2x2 laptop won't have better than 866 PHY speed in ac and that's realistically about 500 mbps single duplex.

Smart 4x4 device can use the extra streams for range - but that only ever works with original firmware, there's a lot of magic and patents involved.